The federal Canadian health agency Health Canada has released a study that found no link between exposure to sound from operating wind turbines and negative health effects.  The study took place over two years at over 1,200 residences within 600 meters of wind turbines in the Canadian provinces of Prince Edward Island and Ontario.  The study collected both self-reported and objectively measured data related to sleep quality, stress and illness, and found that there was no association between these health issues and exposure to wind power sound.  The study also included extensive sound monitoring to evaluate exposure levels of the study participants.  Only six of the 1,238 dwellings in the study had measured sound levels above 45 dBA.  The preliminary study findings released this month will be followed by more in-depth analysis of acoustical data by Health Canada, with a more detailed presentation submitted for peer-review and publication.